Ovarian stromal echogenicity in women with normal and polycystic ovaries

Since the widespread use of transvaginal ultrasound to diagnose polycystic ovary syndrome (PCOS), a cardinal feature has been shown to be the presence of a bright, highly echogenic stroma. This is usually assessed subjectivel y, The objective of this study was to determine whether ovarian stromal ech ogenicity when measured objectively actually differed between women with po lycystic ovaries and those with normal ovaries. A total of 67 women underwe nt a detailed ultrasound assessment before considering assisted conception treatment. Ovarian morphology was assessed and total ovarian volume, stroma l volume, peak stromal blood flow velocity and mean stromal echogenicity we re measured. The stromal index (ratio of mean stromal echogenicity to mean echogenicity of the entire ovary) and total stromal echogenicity were also calculated. Ovarian volume, stromal volume, and stromal peak blood flow vel ocity were all significantly higher in ovaries from women with PCOS. There was no difference in the mean stromal echogenicity, although the stromal in dex was significantly greater in women with polycystic ovaries. The apparen t subjective increase in stromal echogenicity in women with polycystic ovar ies, as exemplified by the greater stromal index, is due to a combination o f the increased volume of ovarian stroma and the significantly lower mean e chogenicity of the entire ovary in these women.